Code of a Killer

First of a two-part drama telling the true story of how a brilliant scientist and pioneering detective united to create the most significant advance in modern criminal investigation. In 1984, Dr Alec Jeffreys, a University of Leicester scientist, unlocks a remarkable technique to read every individual's unique DNA fingerprint. Four miles away, DCS David Baker is a tenacious detective leading the search for the murderer of a schoolgirl. Two years later, a second schoolgirl is murdered and a local teenager is arrested. He confesses to the second murder, but denies the first. Certain that the same man murdered both girls, DCS Baker approaches Dr Jeffreys, whose DNA test has only been used in immigration and paternity cases. Can the test prove the teenager murdered both girls? The community wait anxiously for news that the killer has been caught.

DCS David Baker searches for the murderer of two schoolgirls.

When 15-year-old Lynda Mann turns up murdered, DCS David Baker leads the investigation to search for her killer but struggles to find any worthwhile leads in the difficult case. Meanwhile, scientist Alec Jeffreys works tirelessly to make a breakthrough in DNA research.

The murder of another teenage girl killed in similar circumstances reignites the search for Lynda’s killer. After an arrest and a dubious confession, David approaches Alec and asks for his help on the case.

Possessing what they believe to be the killer’s genetic “fingerprint,” David and Alec initiate the world’s first “DNA manhunt.” But as thousands of samples are tested and costs continue to rise, David worries the operation will be shut down before they can find the killer.